The goal of this project is to investigate respective pathways involved in mRNA biogenesis, and identify potential sequences involved in mRNA trafficking in the nucleus. The results of the proposed studies will provide information on basic cellular functions. Heterokaryons being developed currently will be analyzed by in situ hybridization for the flow of newly created mRNAs' through the chick nucleus to identify other intranuclear RNA biogenesis pathway(s) (not just focus on the nucleolar pathway). In addition, using a chimeric B-galactosidase/mouse c-myc construct which has been shown, in HELA cells using in situ hybridization, to localize to the nucleolus, nested deletions of this chimeric vector will be used to identify c-myc sequence(s) causing intranuclear routing of that transcript. An undergraduate student is currently involved in several different aspects of the current grant, and will continue to be involved in this project.